linux-kernel - Re: [PATCH 4/4] intel_idle: Add SPR support with AMX INIT-state

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Date:   Fri, 05 Nov 2021 15:33:52 +0100
From:   Thomas Gleixner <tglx@...utronix.de>
To:     "Chang S. Bae" <chang.seok.bae@...el.com>,
        linux-kernel@...r.kernel.org
Cc:     x86@...nel.org, dave.hansen@...ux.intel.com, peterz@...radead.org,
        bp@...en8.de, mingo@...hat.com, chang.seok.bae@...el.com,
        linux-pm@...r.kernel.org
Subject: Re: [PATCH 4/4] intel_idle: Add SPR support with AMX INIT-state

Chang,

On Thu, Nov 04 2021 at 15:52, Chang S. Bae wrote:
> +/**
> + * intel_idle_tile - Ask the processor to enter the given idle state.
> + * @dev: cpuidle device of the target CPU.
> + * @drv: cpuidle driver (assumed to point to intel_idle_driver).
> + *
> + * Ensure TILE registers in INIT-state before using intel_idle() to
> + * enter the idle state.
> + */
> +static __cpuidle int intel_idle_tile(struct cpuidle_device *dev,
> +				     struct cpuidle_driver *drv, int index)
> +{
> +	fpu_idle_fpregs();

That's redundant because arch_cpu_idle_enter() is invoked before the
actual idle mechanism. 

> +/**
> + * intel_idle_s2idle_tile - Ask the processor to enter the given idle state.
> + * @dev: cpuidle device of the target CPU.
> + * @drv: cpuidle driver (assumed to point to intel_idle_driver).
> + * @index: Target idle state index.
> + *
> + * Ensure TILE registers in INIT-state before using intel_idle_s2idle() to
> + * enter the idle state.
> + */
> +static __cpuidle int intel_idle_s2idle_tile(struct cpuidle_device *dev,
> +					    struct cpuidle_driver *drv, int index)
> +{
> +	fpu_idle_fpregs();

Ditto

Thanks,

        tglx